The present invention relates to an apparatus for winding coils in slots in electric machinery components such as stators and armatures.
Prior apparatus for winding coils in stators comprise a movable nozzle having a needle for supplying an electric wire into slots in the stator. The nozzle is movable back and forth along the slots and swingable reciprocably for continuously laying the wire as coil turns in the slots to thereby form successively coils in the slots. The coil turns as they are inserted in the slots are freely movable within the slots and thus tend to be displaced into mutually crossing relation, creating "dead spaces" in the slots. Although the coil winding apparatus can wind coils directly in the stator at a higher rate than coils are performed and then inserted in stator slots, the stator slots suffer from the large dead spaces which reduce the space factor of the stator coils, resulting in poor performance of the rotating machinery.
There is known a flyer coil winder for winding coils on the armature of a motor. The flyer coil winder includes a flyer affixed to a spindle and rotatable for continuously supplying an electric wire, and a chuck mounted by a bearing on the spindle and providing a former extending longitudinally of an armature on which coils are to be wound. The wire is wound by the flyer along the former into coils inserted in slots defined in the outer peripheral surface of the armature. Another known coil winding apparatus designed for winding coils on small-size motors has a pair of flyers rotatable in spaced orbits in opposite directions about a common axis extending perpendicularly to the axis of the motor armature. The coils as they are formed by the flyers are guided by formers into the slots in the armatures.
The formers in these known flyer coil winders are fixed to chucks and spaced sufficiently from the armature so as not to interfere with finally placed coils when the armature is indexed so that all of the coils can be wound in place. Since the formers can guide the wire only up to entrances of the slots, the coils placed in the slots are loosened and freely movable therein. The wire as inserted in the slot tends to be positioned closely to one slot wall, is wound into a few coil turns up the slot wall, and then the coil turns are collapsed in the slot. The coil turns therefore cross each other and are loosened in the slot, thus adversely affecting any successive coil turns inserted in the slot and producing a dead space therein. When the coil is wound up, it closes the entrances of adjacent slots and prevents coils from being inserted in the adjacent slots, and coil ends interfere with each other and swell at the exits of the slots. This increases the space factor of the coils in the slots to the point where no wedge can be inserted in the slots.
The conventional coil winders therefore fail to prevent the successively wound-up coil turns, the crossing of the turns, the dead space, and the interference of the coil ends. Accordingly, no coil winders have been available for winding coils neatly in armature slots with a high space factor of the coils in the slots. The space factor of the coils in the armature coils has been up to about 57% for thick electric wires and about 60% for thin electric wires. To construct small-size and high-output motors, it is the best way to increase the space factor of the coils in the slots as it does not largely affect the temperature rise of the motor and the useful life of the brush.